Method of making rigid foam composition



'lcialfiias Patented Jan. 29, 1952 \J' pl m V NoDrawingfApplicationApriI 26,190, If Y ,j q lfl -afi 'i sum c. (c1. ins-12: .4: I, i 1 7v I a-.- 12. ff This invention relates to s protein foam comon comma watemroonngprwainr resistinguimsition and method of manufacture. i terial of *which'fasphalt is an example; 5 The 'invention is particularly useful in mok Using-the method end-the composition "-de thermal insulating ioam'board and-willilbe scribed,-I have made 'ioamboards of density as illustrated 'by desc 'tionflrstin connectionwith 5 low' as i tozpounds to the 'cuhic-ioot, with a Lsuch h n, I v coemcientoijthermal conductivity around D2 1 It has been known that glue foams can be set to 0.'3 in the engineering system oi'imitsfthe air and made into shaped articles of low density cells 'in the finished product j-being"closed nnd "and low coeflicient-of -thermal conductivity. practically uniformly distributed thronghout In spite of theseandother known -'desirahle 10. the: entire-mass, In allinetances} the product of propelties foifthe foams, *diillculties inherent in the present inventio i j 31 1 m' m m -g :theprpce ss ""o1" 'anuiacture and disadvantages. protein iorms'a continuousstructure'and'isthc .bi'ith ilni hed'fp o c fh ;?e e d t wnti srn se: h srth lim i w l yelpment oitheioam insulation' onacommer airis-the'discontinuous phase; I, I f f' 'i eioaii ha e q i in w ele im efwslw i he t e temperatures such-es those'freclosely spewedand I 'i ieithi ish uiithesfim e -strives r'epare as heretofore-aud "They -decrease the-mrmnessjfandj zire oh -Yer; b ittl fine: newer. Qt mummies con ce Show 'i le, here tenem ts; i bfi lsmi niiiina s s 7 Y i i q wh wieid file ioamstructure'"duringiormatiorraniidryinfio! lsojprgmpkj lffl bmn .i the foamboard, lack MW and mgi er'gran iorthematic iriw tacci ent' jcepfihility of the foam to mold and tofattaclgpy ally or hypo densationduring use. frhejeiiect insects, rodenis apd lilze,grumals-futilizing pruof the nbers is bestdemonstrated jiud gimanu teinas aiood." lecture of the block. *with the 'nheremixed 1 f, Theipresent invention provides a protem ioam throughoutthe wet foami the ,foamzmayfhe'jfdned romposition and method that-makes possibie the quickly and eiiectively atf looj*c.,i wltnjtne pro- V rapid production of lightweight articlessuch-as iduction of. a. pood e-n n; produgt V :ioamhoard. that are stable duringnrying atgl e fi s m fedicompositio, 4 are. prated gtemperatures; *retainfihe *gas' fhulibles in comparaole'gg cannot dried f "satlsiaciorily; a me are'mhffight'mweimi "ar s h fhieh tempFratuI h siha insl n: d'- ijtojinol e i :35 3. i-

inimalslflreeof objectionable odorjand. not the rotem-1isedi"eme hirer-healing s e" ,peadilydisintegrated bywaten-eee nisfactory and is preierred It'requu'es nofmd. -g Briefly stated, the inyention c ses-the ar biliting agentto item the water in ticle resultingirom and the methodvof making en s 'thejpreparation oithe initial solution. 1. aqueoussolution of ewatersoluble protein om- As the-agentdiss lvedwith the 'proteinior'the position, inorganic proteinv insoluhilizingmnd purpose -01 ultimately insolubilizing "and toughtoughening agent, and an anion-actiuetsurta'ce enin'g or hardening the protein, there is used tension lowering material serving as a foaming a water 'solubleinorganic protein tanning ag'ent agent or forming assistant, admixing a fibrous selected from the group-consisting'ot chromium, reinforcing material serving to increase .the 46 aluminum and ferricsalts. Examples of such average fineness of the bubbles. increase the agents that are particularly satisfactory are strength, and decrease the brittleness of the'finsic ro uma u um su ate. and ished product, foaming the resulting mixture by r sulfamicularly satisfactory results introducing gas in subdivided form have :beenobtained'witha'soluble'chromiumealt, 'andthen drying the foamed mass at an-elevated #50 i. e. the sulfate, chloride, or acetate, and-that is temperature. In the form preferred 'for comthe agent which is'recomniended [or commercial mercial use, the 'foaxned solution .is .shapcd'rinto use, the sulfate 'being especially satisf-e tory'and a board on a sheet element such as krait paper; thebasic sulfate'being prei'erred.-

on drying, the composition adheres to the sheet The use of these inorganic tanning agents also element. In a modification. the product includes introduces into the protein compositions resistance to mold and unpalatability or toxicity of the tial distribution of air or other gas during thefoaming of the solution and stabilizes the dispersion, there are used anion-active surface ten-f sion lowering agents, as, for example, water soluble salts of alkyl aryl sulfonates suchas .the sodium salt of keryl benzenesulfonatastraight -or, branch chain alkyl sulfates (sulfated alcohols) of which an example is sodium lauryl sulfate, a

branch chain C14 alcohol sulfate and oleylm ethyl taurine sulfonate. As shown herein, these surface tension lowering agents are efiectivein con-G tact with all my ingredients. They are effective, ion-instance, in contact with the various tanning a ents includlngthose salts'which as used by me give ions of-the metals selected from thegroup consisting ofchromiumgaluminum and iron,

,- The gasbeaten into form the foam is ordinariaoprovideailionl rt of; the.. flber,component. alwate p fihi es fi la ii a b-i fitgd fmeiare' o lo td rflr necessary. howeve'rgespe whenthelioamedflprotein product is- .to b

iwe iiinirheudm iarsnbn.n ersialsommbe.use

' .elu nimu ii d d a into. the foamjoompositiongthere fis b ad'- 1 yant sd liexnefl ive ucli asasphfilt. W

' emmsions;"or'water.repellentsoaps sultablyjprefcipitatedln t solution. ("ifv the "protein composiijzion before or at'about the time or the foaming.

fjas'jto proportions,;considerable variatigns are .leil QIt is essential; owever, that the protein jbeiused impro r ioit t weter pr e th tim of goamingso gsto givea solution that isatleast of jatheg'highiboncentration Zof the protein. Thus,

new" is usedipreferablyji toj 1ppoundsjjof the protein to 100 poundsof water although for some pu o es ranse-maxbe made somewhat greatfil ayftoflfipa '1..';;i";t.. .1 .;;.i It is important tithe ratio. 'of protein to the fibrous strengthening agent should be large so that menmsned 'productis. essentiallya fiber reinforced protein foam in set condition. rather than simply a' bondediibrous product.- Thus, the proportion of the protein to fibrous material is ordinarily about 30 to 100 parts of the protein for 100 of fibrous material, best commercial results being obtained when the ratio is about 40 to 60 parts .of the protein. More fiber than 100 parts cannot be properly distributed throughout the foam. particularly in the case of cellulose flu-fl or other wood pulp.

The protein insolubilizing and toughening agent is usedin the proportion adequate to give the desired toughening and insolubilizing effect. Additional quantities are unnecessary. Preferably the insolubilizing and toughening material is used in 4 the proportion of 5 to 20 parts for 100 parts of the protein, although an article that is sufllciently tough and strong for most purposes may be made when the proportion of the insolubilizing and 5 toughening agent is as low as 3 parts. Also the proportion may be increased up to about 40 parts for 100 parts of the protein, although such large proportion is unnecessary and uneconomical for most purposes. Ordinarily about 12 to 20 parts 1o of the insolubilizer are used.

. 1 The foaming agent is used in amount to lower thes'urface tension or cause the bubbles of air when introduced to become suspended in finely -:,;5 divided. form. :substantiallypermanently in the 15 presenceof the fibers and other materials present. The foaming agents are used in accordance with manufacturer's directions and conventional practice as to the amount of each that is ordinarily usedpto'lo'wer the surface tension of water in contact with solids. This amount is ordinarily about .5 to 15 parts to 100 parts of the glue and the surface tension .is .not lowered-in proportion as. the amount of the foaming agent is increased above the amount that is commonly used for the selected foaming agent .to lower the surface tension of its aqueous solution. The proportion of 5 to 15 parts of the surface tension lowering agent for 100 of glue corresponds, when the glue varies from 4 to 15 parts for .100 of .water, .to O.2 to 2.25 parts .of the saidagent for 100 of waterli; ,g T

.. Waterproofing. when used is. incorporated in exclude water or decrease the absorp- .tion of-vapor from humidifiedair without making the. .waterproofed' article objectionably ,jheavy and therefore low in thermal insulating power. with the insoluble soaps, paraflin ,w'ax emulsions or the like, about 2 to 19 parts b'yjweight are adequatefor 100 parts of the proteinmaterial. With asphalt, wa'x tailings, ,and less eflective water e repellents-the proportion'maybe higher, as for proteinn 'aterialjgin composition: Z.

instance,- 59%. to 80%,. or. so of. the weight of, the

the ingredients ay 'thusbe summarized as fol- I .-c f 'Pounds Glue, preferably hide glue 100 Mineral tanning agent, preferabLv' .f basic chromium sulfate 3.0',to" 40 Preferably .12 to 20 Foaming agent 5 to 1 15 g Preferably. ..'10 Fibrous-filler 150 to] 330 if- Preferably 165 to 250 :5 Water 660 'to 2500 Preferably" 1000 to 1660 On a dry basis the protein constitutes at least about of the composition, disregarding the 80 added fibrous filler. v

The invention will be further illustrated by description in connection with the following specificexamples.-

' Example 1 8 pounds of a hide glue having a jelly strength of 334, a viscosity of 109 millipoises, a grease content of 0.19%, and good foaming characteristics is dissolved in 72 pounds of water. 13 pounds of a 10% aqueous solution of a surfaceactive alkyl aryl sodium sulfonate (foaming agent) is added and the mixture heated to 60 C. 7 pounds of a 10% solution of a basic chromium sulfate having a basicity of about 33% 15 added to the above mixture with stirring Just be- 5 fore foaming is started. Foaming of the hot I ..?J.......,a a

CRUSS REFERSQE solution is carried out continuously with an airlift-baiile type apparatus such as described in U. SaPatent 1,140,548, of Vogelsang or in Industrial and Engineering Chemistry, vol. 28, pp. 422-3 (1936). Such an apparatus using a 40- mesh screen and operating at 60 pounds air pressure is adjusted to produce 6 gallons of foam per gallon of glue solution per minute. A low density fibrous filler such as A-l alpha-cellulose fiufi is immediately mixed into the foam by means of a suitable heater or mixer in the proportion of 1 pounds of fiufi to 6 gallons of foam. The mixture is then formed into sheets one inch thick or more on suitable screen belts or sections lined with a 10 or 20 pound kraft paper. The foam is dried at 110 C., to yield a strong rigid insulation board covered with an adherent sheet of light weight paper and having a density of about brittle, friable product obtained upon drying has 2.8 pounds per cubic foot. The paper coating may be applied to one or both sides of board and serves both to overcome sticking to the supports during drying and to permit easy and economical application of the usual waterproofing and water vapor impermeable coatings if desired.

Example 2 bilized, dispersion of petroleum asphalt having.

a solids content of 53%. 2.5 pounds of a branch chain C14 alcohol sulfate, a commercial solution containing 25% sodium'tetradecyl sulfate as the active foaming agent, are now stirred in and the temperature is broughtto 30 C. 18 pounds of a 10% solution of basic chrome sulfate having a basicity of about 33% is added to the above mixture with stirring just before the foaming operation is started. Foaming is accomplished by beating airinto the composition in a wire whip mixer operating at350 thermal insulation value is obtained. This Prod- R. P. M. 15 pounds alpha cellulose are then introduced and stirred into the foam Upon shaping and drying theresulting foam, a strong rigid board having excellent density of about 1.4 pounds per cubic foot and is readily shredded or powdered. This may be employed as a low density loose-fill insulating material or as a filler for insulation board prepared as in Example 2.

It will be understood that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention. 2

Thi application is a continuation-in-part of my prior application Serial No. 535,895 filed May 16, 1944, now abandoned.

What is claimed is:

,1. The process of producing a substantially rigid, lightweight thermal insulating product which comprises forming an aqueous solution containing 100 parts by Weight of water, 4 to 15 parts of animal protein glue, 0.2 to 2.25 parts of an anion-active surface active agent, a water soluble animal protein glue tanning salt selected from the group consisting of a water soluble animal protein glue tanning salt of a metal selected from the group consisting of chromium, aluminum and ferric iron; and incorporating air through said aqueous solution to form a tough stable glue foam; and then mixing short length,

'non-comminuted fibers with said glue foam in proportion of about 30 to 100 parts of glue to 100 parts of fibers; shaping the resulting mixture to the form desired and drying the shaped product.

2. The process of producing a substantially rigid, lightweight thermal insulating product which comprises forming an aqueous solution containing 100 part by weight of water, 4 to 15 parts of animal protein glue, 0.2 to 2.25 parts of an anion-active surface active agent selected from the group consisting of alkyl sulfates and alkyl aryl sulfonates, a water soluble animal protein tanning salt selected from the group consisting of chromium sulfate, aluminum sulfate and vQferric sulfate; and incorporating air through said uct, containing asphalt, is characterized by a greatly improved resistance to water and watervapor pick-up as compared to similar boards prepared without asphalt.

Example 3 The procedure of Example 1 is followed except temperature of drying is about 30 C.

The use of this low temperature requires a very long time of drying, the low temperature being (about 1.6) odorless, and flameproof.

Example 4 Foam prepared continuously at 60 C. as in Example 1 but without added filler is spread onto a 16-mesh screen belt in a layer about inch thick and is dried continuously at 110 C. The

' that (1) the fibrous filler is omitted and (2) the I aqueous solution to form a tough stable glue foam; and then mixing short length, non-comminuted fibers with said glue foam in proportion of aboutv30 to parts of glue to 100 parts of fibers; shaping the resulting mixture to the form desired and drying the shaped product.

3. The process as claim 2 in which the tanning agent is basic chromium sulfate.

4. The process of claim 2 in which the glue is hide glue.

5. The process of claim 2 in which the tanning agent is basic chromium sulfate and the glue is hide .glue'.

PAT MACALUSO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,782,383 Greider Nov. 18, 1930 2,282,190 Jahjoh May 5, 1942 2,433,849 Lathrop et a1. Jan. 6, 1948 

1. THE PROCESS OF PRODUCING A SUBSTANTIALLY RIGID, LIGHTWEIGHT THERMAL INSULATING PRODUCT WHICH COMPRISES FORMING AN AQUEOUS SOLUTION CONTAINING 100 PARTS BY WEIGHT OF WATER, 4 TO 15 PARTS OF ANIMAL PROTEIN GLUE, 0.2 TO 2.25 PARTS OF AN ANION-ACTIVE SURFACE ACTIVE AGENT, A WATER SOLUBLE ANIMAL PROTEIN GLUE TANNING SALT SELECTED FROM THE GROUP CONSISTING OF A WATER SOLUBLE ANIMAL PROTEIN GLUE TANNING SALT OF A METAL SELECTED FROM THE GROUP CONSISTING OF CHROMIUM, ALUMINUM AND FERRIC IRON; AND AND INCORPORATING AIR THROUGH SAID AQUEOUS SOLUTION TO FORM A TOUGH, STABLE GLUE FOAM; AND THEN MIXING SHORT LENGTH, NON-COMMINUTED FIBERS WITH SAID GLUE FOAM IN PROPORTION OF ABOUT 30 TO 100 PARTS OF GLUE TO 100 PARTS OF FIBERS; SHAPING THE RESULTING MIXTURE TO THE FORM DESIRED AND DRYING THE SHAPED PRODUCT. 